Case Studies

Reverse Engineered Woodward Governor


LEARN MORE: SOLVE YOUR PARTS AND EQUIPMENT OBSOLESCENCE ATC Nuclear has a long-standing relationship with many utilities built over years of providing them with hard-to-find components, outage support, and general sourcing projects. ATC Nuclear was approached by one of these utilities to find a source for existing Woodward Governor parts. The plant site was a two unit site with only one unit operating, and over the years, the operating plant had salvaged parts from the other unit. When the plant decided to restart the second unit, it was discovered that several of the Woodward Governor parts on the Terry Turbine were obsolete. These governors are used to control the speed of a turbine.

The utility wanted to use identical controls within the two plants, however the OEM developed a digital controller and discontinued support of the installed equipment. Discovering there was a depletion of available parts in the surplus market, ATC’s Instrumentation & Controls Lab (I&C) pursued reverse engineering the critical Woodward parts. In order to begin this process, previously used and qualified Woodward parts were obtained through the utility and our expansive warehouse to use as specimens for the reverse engineering and replication process.

Original EGM Control Box
The individual replicate boards and components that comprise
the ATC version
Ramp Generator & Signal Converter
Manual Speed Controller

ATC Nuclear’s Innovative and Reliable Solution

ATC chose to reverse engineer and replicate the original controls to support the customer. The reverse engineering process involves redrawing a system schematic by tracing every electrical connection of the sample, identifying all of the discrete components, generating Gerber files to manufacture circuit boards, measuring mechanical components, composing manufacturing drawings, analysis of electrical and mechanical components, procuring necessary parts, assembling, and testing. At the conclusion of testing a successful prototype, Engineering Equivalency Reports and Dedication plans are generated and submitted to the customer for their approval.

Although this is a single example of the many configurations of this EGM Box, ATC’s I&C Lab has repaired many of these controls in addition to converting one configuration to another.

Another component that comprises the Governor Control System is the Ramp Generator and Signal Converter (photo to right). The original box is on the top and a replicated ATC version is on the bottom. The replicated version performs identically to the original version.

The customer also needed a Manual Speed Controller, but unfortunately, a sample could not be located for reverse engineering. Instead, ATC’s I&C Lab used customer photos and OEM drawings to manufacture and qualify(both electrically and seismically) a controller to fit the application, as seen in the photo to the right.

An Overspeed Monitor was the final component necessary to complete the control system. The unit was obsolete and was reverse engineered using a sample from our warehouse. The OEM enclosure was originally cast out of aluminum and ATC determined it was more economical to manufacture the enclosure out of aluminum block. ATC generated a manufacturing drawing and had the enclosure manufactured to within 5% of the weight of the original enclosure. The photo below shows a 3D model ATC generated for the enclosure manufacturing:

In addition to solving the utility’s obsolescence issue, ATC Nuclear has the ability to supply new reverse engineered Woodward Governor components for other nuclear and non-nuclear utilities around the world. The Woodward Governor components are a small example of the reverse engineered and manufactured products the I&C Lab is capable of producing.

Several utilities have addressed the obsolete part issues for the Woodward Governor system by modifying their entire governor control system with an OEM digital upgrade. However, these modifications may take years to implement. ATC can support the original analog control system until such upgrades are improved and installed. This is just another example of the innovative solutions offered to ATC customers to maintain the safe operations of the nuclear plant fleets worldwide.

On the left: the Original Overspeed Monitor
Circuit Board design package us by the I&C Lab to generate the schematics and circuit board layout drawings for the Overspeed monitor

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